October 20, 2017

09.06.10: H2O in the Solar Neighborhood.

NASA's InfraRed Telescope Facility. (Credit: NASA/Institute for Astronomy).

NASA's InfraRed Telescope Facility. (Credit: NASA/Institute for Astronomy).

 

   Water, water, everywhere… over the past year or so, evidence for water in the solar system has been mounting in some unlikely places. The poles of our Moon. Ice geysers on Enceladus. Now add the denizens of our asteroid belt to the list; earlier this year, scientists at the Johns Hopkins University of Applied Physics in Laurel, Maryland have revealed findings that water ice may pervade the surface of asteroid 24 Themis. This comes from six years of careful study carried out by astronomers Andrew Rivkin and Joshua Emery using NASA’s Infrared Telescope Facility. By studying the asteroid of seven separate occasions, a definite signature pattern of water ice and carbonaceous organic materials has emerged. Much like the revelation of water hydroxyls on the Moon, this comes as something of a shocker; the asteroids bordering the inner solar were long suspected as being bone dry. 24 Themis orbits the Sun at a distance of 297 million miles, or about 3 A.U. “This is exciting because it provides us a better understanding about our past and our future,” stated Don Yeomans of NASA’s Near-Earth Object Program office at JPL. Clearly, the possibility of a “wet asteroid belt” may have further implications not only for space travel, but as to the origins of terrestrial water as well. Keep in mind, the ratios mentioned are often minuscule in an everyday sense; for example, the amount of water reckoned on the lunar surface during last years’ media blitz was on the order of one liter per ton of lunar regolith. Clearly, it will be a major technical feat to harvest such a small amount in useful quantities. Obviously, many sources of extraterrestrial water are still bone dry by the standards of the harshest terrestrial desert. Still, this tantalizing find may provide clues to fuel speculation as Dawn mission enroute to the asteroids Vesta and Ceres draws near; Vesta displays a curious reddish brown spectrum highly suggestive of a tarry surface, and Ceres has been proposed to perhaps harbor a subterranean ocean similar to what’s thought to exist beneath the surface of Jupiter’s large moon, Europa. This all begs for further exploration and could drive a new emphasis towards the President’s eluded to “Mission to an Asteroid” by 2030 or so… Apophis in 2029, anyone?

27.04.10-Does Planetary Gravity “Stir up” Asteroids?

(Credit: Hayabusa/JAXA).

(Credit: Hayabusa/JAXA).

 The bizzare world of Itokawa as seen from Hayabusa.

   Asteroids are probably the most intriguing bodies in our solar system. More than just errant chucks of rock, these tiny worlds may hold the key to early planetary accretion. Several mysteries about these bodies persist; are they single slabs of rock, or loosely held together rubble piles? The question may be more than just an academic one, especially if we want to move one of these celestial missiles headed our way. Now, researcher Rick Binzel of MIT has noted a curious factor about many Near Earth Asteroids (NEA’s); nearly all which have experienced close passages near the Earth have seemed to undergo a spectral change. Specifically, the study looked at simulations of the orbits of 95 NEAs. Most are of the S-type, showing a reddish, sun burnt spectrum indicative of solar wind blasting for several million years. About 20, however, show a Q-type resurfacing, as if they had been “freshened up” somehow. Q-type asteroids are of the same spectral class as ordinary chondrite meteorites found on Earth, and are almost never observed in the main asteroid belt. Tracing back their orbits, all 20 show evidence of passages closer to the Earth than our Moon sometime in their history. Scientist Pierre Vernazza of the European Space Agency estimates that asteroids can be reddened by solar wind exposure in about one million years. Looking at asteroids such as 25143 Itokawa imaged by the Japanese Space Agencies’ Hayabusa spacecraft, one can easily imagine such a loose collection of rock experiencing massive landslides as it passes the massive Earth. Such an event may even splinter the main body, as happened to comet Shoemaker-Levy 9 in 1992 when it was torn apart and ultimately impacted Jupiter. And we have an unprecedented opportunity to study an NEA in 2029, when asteroid 99942 Apophis swings by Earth at a distance of about 20,000 miles above our surface. “My vision is that we would have (Apophis) all wired up and monitored so that we can listen to it creak and groan as it flies by,” says Binzel. Knowing what kind of shifting terrain they face might also be of vital importance to future visiting astronauts. A mission to such a body was stated by president Obama in a recent address given at the Kennedy Space Center. Clearly, these bodies are of unparalleled interest… all eyes will be on the Australian desert on June 13th of this year as Hayabusa returns to Earth. Did it successfully grab a sample of an NEA? Researchers won’t know for sure until they have the sample return canister in hand!

29.01.10: A Failed Vision: Where does the U.S. Space Program go from here?

The launch of Ares X-1 last year; a one shot rocket? (Credit: NASA/Sandra Joseph/Kevin O'Connell).

The launch of Ares X-1 last year; a one shot rocket? (Credit: NASA/Sandra Joseph/Kevin O'Connell).

By now, everyone in the astro-blogosphere has heard the bad news concerning the Constellation program. No Ares. No Mars. No permanent presence on the Moon. This week’s announcement of Congress failing to provide funding for the future manned space program comes as a tremendous blow to all who work in and follow the space industry. All we’re left with is the vague promise of the development of a heavy lift rocket to get us out of low-Earth orbit, a promise that might be over a decade from lift-off… at this point, it seems as if we may be headed towards another lean decade, much like what struck the space program in the 70’s after Apollo.

But is there hope? Certainly, the dual forces of crisis and opportunity may well come into play here. While the shuttle program is coming to an end, the extension of the International Space Station out to 2020 assures us that our manned presence in space will indeed continue. Scientists and astronomers may quietly breathe a sigh of relief, as the axe didn’t fall on their pet space probe, and funds for small shoe-string unmanned projects won’t be sacrificed to the dollar-guzzling manned space program.  Perhaps, as some might argue, the “Apollo on steroids” approach lacked the vision to truly grab the public’s imagination and was doomed from the start. But all would ultimately acknowledge that we truly need both, a robust manned program and a diverse unmanned space exploration program. It’s true; we are in financially troubling times. Unfortunately, space exploration tends to wind up on the short list of many inside the beltway as they search for perceived pork barrel projects to cut. But history has shown that nations that cease exploration and curiosity tend to end up as historical has-beens’ as they become introspective and withdrawn. Perhaps the sight of Chinese or Indian astronauts setting up shop alongside our hallowed Apollo sites will be enough to inspire a new space race… but will it be too late? “How could this have happened?” the credulous public will then say… how did we end up so far behind?

We here at Astroguyz believe now is the time for vision and action in space. What’s needed are some truly innovative plans for exploration; how about a manned mission to an NEO such as Apophis in 2029? Or funding the shelved Terrestrial Planet Finder?  Or further exploratory landers for Europa or Titan? A heavy lift platform also gets astronomers wheels spinning as to the payloads it could launch. Now might be the time to dust off some of those innovative alternate plans that engineers were said to have been moonlighting over years back. But one thing is certain; any new drive into space must be accompanied with a twin drive in science education as seen in the 60’s to be truly effective. This week’s news may have been a major setback, but there are lots of intriguing options out there; let’s get out of low-Earth orbit and back into deep space exploration, this time, for good!